Molten salt batteries are of interest commercially because of their high energy content per unit weight, high cell voltage and high current (energy) delivery capacity. In particular, molten salt batteries with lithium type electrodes exhibit high voltages which result in unusually high capacity per unit weight and unit volume.
Long shelf life is advantageous for many applications, such as where the battery is only used occasionally (e.g., standby sources of power for memories, electronic devices, telephone equipment, etc.) or where the devices are stored for long periods of time before use. Because of high capacities and high discharge rates, molten salt batteries are potentially useful for a large variety of applications. Recent concern about energy shortages suggests the use of such batteries in electric vehicles and as energy storage devices for more efficient use of present energy producing facilities.
A particularly difficult problem associated with molten salt batteries is to obtain a battery design which will be rechargeable without seriously degrading the high capacity per unit weight characteristic of such batteries. In particular, it is desirable for many applications (e.g., electric vehicles and load leveling applications) to have an extensively recyclable battery which will maintain over many cycles its high capacity per unit weight.